Acta Anaesthesiol &and 1992: 36: 46+473

Perioperative complement activation in neonates under halothane or fentanyl anaesthesia K. MIKAWA, N. MAEKAWA, R. GOTO,H. YAKUand H. OBARA Department of Anaesthesiology, Kobe University School of Medicine, Kobe, Japan

We investigated perioperative changes in complement activation in 18 neonates undergoing elective abdominal surgery with or without thoracotomy by measuring plasma concentrations of C3a and C5a, and leucocyte counts in peripheral blood. The 18 neonates, ranging in age from 1 to 17 days, were randomly divided into two groups according to type of anaesthetic procedures; the “halothane group” consisted of nine neonates in whom general anaesthesia was maintained with halothane and nitrous oxide (N,O) in oxygen, while the “fentanyl group” consisted of nine neonates in whom general anaesthesia was maintained with fentanyl and N,O in oxygen. Plasma C3a and C5a concentrations were higher in the fentanyl group than in the halothane group during the perioperative period. We have demonstrated that abdominal surgical trauma caused complement activation even in neonates undergoing the fentanyl rather than the halothane anaesthesia. Further studies are required to elucidate the precise mechanisms and the clinical implication of perioperative complement activation in neonates. Received 29 314,accepted for publication 18 Nouembcr 1991

Key words: Anesthesia: fentanyl, halothane, neonates; complement activation: C3a, C5a

It is well known that complement activation participates in the development of acute respiratory failure ( 1 ) . C3a and C5a, biologically active products of complement (anaphylatoxins), play a key role in this pathophysiological state by causing accumulation of neutrophils in the lung and/or activating mast cells. Several researchers found that soft-tissue trauma (2) and cardiopulmonary bypass (CPB) (3) caused complement activation, possibly leading to postoperative acute respiratory failure. In neonates, however, no reports regarding perioperative complement activation have been published because such measurements require large blood samples. The development of radioimmunoassay (RIA) methods has recently made it possible to measure plasma-activated complement concentrations even in small samples and has stimulated studies on complement activation in children undergoing cardiac surgery (4). It is also well known that perioperative stress produced by surgery is partly involved in postoperative immuno-suppression (5-7). It is likely that there is a difference in stress response to abdominal surgery between halothane- and fentanyl anaesthesia (8). Thus, the two anaesthetic procedures probably lead to different immune responses to surgery, even in neonates. The current study was designed to assess perioperative complement activation in neonates undergoing abdominal surgery with or without thoracotomy under

halothane or fentanyl anaesthesia. To make this assessment, we measured plasma C3a and C5a concentrations during perioperative periods. PATIENTS AND METHODS Subjects The protocol for the study was approved by the Human Investigation Committee of Kobe University School of Medicine, and informed consent was obtained from the parents of all patients. Plasma concentrations of C3a and C5a, and leucocyte counts in peripheral blood were determined in 18 neonates (ASA physical status 2), ranging in age from 1 to 17 days. They were also randomly divided into two groups as follows: nine neonates anaesthetised with halothane and N,O in oxygen (halothane group), and nine neonates anaesthetised with fentanyl and N,O in oxygen (fentanyl group). Table 1 gives the general data on the two groups. All the patients underwent abdominal surgery with or without thoracotomy. Four regular surgeons participated in the current study. No patients had a clinical history of infection; nor had they taken steroid or immunosuppressive agents. Anaesthesia Anaesthesia was induced with N,O 4 I/min, oxygen 2 I/min, and halothane in gradually increasing concentrations up to I .O%-I .5%. Immediately after onset of sleep, atropine sulfate, 0.01 mg/kg, and vecuronium bromide, 0.1 mg/kg were administered i.v. and all patients were intubated. Halothane was discontinued in the fentanyl group patients. Anaesthesia was maintained with 0.5%-1 .O% halothane and 50-60% N,O in oxygen in the halothane group, and with fentanyl 2 5 4 5 pg/kg (initial dose 15-20 pg/kg and additional dose 10-25 pg/kg) and 50-60% N,O in oxygen in the fentanyl group. Muscle relaxation was obtained with intermittent administration of vecuronium (total dose 0.254.5 mg/kg) in all patients. No drugs

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K. MIKAWA E T AL.

Table I Data of operation and patients. Values are expressed as mean f s.d. or median values and ranges given in parentheses. Halothane

Fentanyl

9 7/2 6.8 f 3.0 38.4k 1.1 2589f387 3.67 2 1.1 2.96 f 1.0

9 6/3 7.2 f 3.4 38.2f 1.2 2677f415 3.41 f 0.67 2.65 + 0.81

~

11

Sex (M/F)

Age (days) Gestational agr (wreks) Weight (g) Ihration of anaesthesia (h) Duration of operation (h) During anaesthesia Infusion (ml) Transfusion (ml) Bleeding (gm) Urine output (ml) Surgical stress score* Abdominal surgery With thoracotomy Without thoracotomv

I I5 (45-1 35) 30

LO- 135) 50 10-130) II (3-18) 12 (6-1 7)

I 8

100 (50-130) 85

(10-1 LO)

65

( 1 0 - 1 30)

12 (4-22) 13 (5-15) 1

8

P

Perioperative complement activation in neonates under halothane or fentanyl anaesthesia.

We investigated perioperative changes in complement activation in 18 neonates undergoing elective abdominal surgery with or without thoracotomy by mea...
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